Concussion Correlates with Abnormal Brain Structural Patterns

Concussion – even mild, potentially has a persisting effect even after the resolution of clinical symptoms.  Andrew R. Mayer, from the at the Lovelace Biomedical and Environmental Research Institute (New Mexico, USA), and colleagues enrolled 50 subjects within 3 weeks of injury, along with an equal number of healthy matched controls, in a study.  Diffusion tensor imaging in 26 patients with mild traumatic brain injury (TBI) showed increases in mean fractional anisotropy, a marker of gray matter injury, in the superior frontal cortex that persisted on the left side 4 months after the injury in the patients relative to healthy controls.  At the 4-month evaluation, subjective complaints of mental dysfunction had subsided, matching those seen in the control group, as did performance on objective neuropsychological tests. The study authors observe that: “Increased cortical [fractional anisotropy, a marker of diffusion] is largely consistent with an emerging animal literature of gray matter abnormalities after neuronal injury. Potential mechanistic explanations for increased  [fractional anisotropy] include cytotoxic edema or reactive gliosis.”